When Tomcat starts a web project, it reports bad version number in. Class file (unable to load Class ...) Error

I. Problems Found
This error is reported when you start the Tomcat console.

Ii. Cause
The JDK version of Tomcat is different from the JDK version of The. Class.

Iii. Solution

Step 1: view the JDK version and location of myeclipse

Window-> preferences-> JAVA-> installed jres.

Step 2: view the compiler version of myeclipse

Window-> preferences-> JAVA-> Compiler

Step 3: view the compiler version of a specific project

Project Properties> JAVA> Compiler

The compiler version of myeclipse is equivalent to providing global guidance. You can set different compiler versions for specific projects.

Step 4: view the JDK version of Tomcat

Window-> preferences-> myeclipse-> servers-> tomcat-> tomcat6.0-> JDK

Be sure to use JDK of the same version and location as the problematic project.